Triple valve



(N o Model.)

W. E. PRINDLE. TRIPLE VALVE.

No. 568,888. Patented Apr. 21, 1896.

X H 1m; 2 8 Z 7t B l l \VILLIAM E, PRINDLE, OF AURORA, ILLINOIS.

TRIPLE VALVE.

SPECIFICATION forming part of Letters Patent No. 558,838, dated April21, 1896.

Application filed May 27, 1895. Serial No. 550,862. (No model.)

To all whom it may concern.-

Be it known that I, WILLIAM E. PRINDLE, of Aurora, in the county ofKane, and in the State of Illinois, have invented certain new and usefulImprovements in Triple Valves; and I do hereby declare that .thefollowing is a full, clear, and exact description thereof, referencebeing had to the accompanying drawing, in which the figure is a verticalsection through my valve, the full lines showing the moving parts intheir positions when the brakes are off and the dotted lines thepositions they occupy when an emergency stop is desired.

The object of my invention is to provide a triple valve for air-brakesystems of such construction that its first cost will not be great, itsrepair not require skilled labor, the wear of parts he reduced todiminish the necessity for frequent repair, and which, withal, will bemost efiicient and satisfactory in operation.

To these ends said invention consists in the triple valve having theconstruction and combination of parts substantially as hereinafterspecified.

The body or casing of my valve consists of but two parts, an upper one,A, andalower one, B, that are suitably bolted together. The upper partis provided with means for the connection of the valve with thetrain-pipe and brake-cylinder, respectively, while the lower part isprovided with means for con nection with the car-reservoir. Said meansmaybe any of the usual expedients employed to enable the coupling ofparts such as those referred to.

The train-pipe connection at places said pipe in communication with achamber Gin the upper casing part A, which chamber through a port orpassage a communicates with a cylindrical chamber D, that is formed inthe upper portion of the lower casing part B, and which chamber in turnis connected by a small port E, at the bottom thereof, with thecar-reservoir connection I). Closely fitting and movable vertically inthe chamber D is a piston 1*, having on its under side an extension G,that is cylindrical in form and closely fits a cylindrical chamber II,the bottom of which is provided with a seat in the form of an annularrib 71,, upon which the lower end of said extension G is adapted to restand act as a valve.

The valve-chamber H has opening into it a horizontal port I), thatconnects it with the car-reservoir port I), and connecting said chamberH with a chamber I in the lower portion of the casing part B is avertical passage K, which chamber I communicates by means of a smallduct iwith the open air, and by means of a passage way L, formed in bothcasing parts A and I with the brakecylinder.

A puppet-valve M in the chamber I is adapted to close and open the ductor exhaust-port i, and it is guided in its movements up and down forsuch purpose by a vertical stem an upon its upper side that enters thepassage K and a stem m upon its lower side that enters an opening n in ascrew cap or plug N, which forms the lower side of the chamber 1. Acoiled spring or within the opening it engages the lower end of the stemm and operates to lift the valve, when permitted so to do, to close theexhaust-port i. As the function of the valve M is simply to control theegress of air through said port, provision is made for the passage ofair from the chamber H through the passage K to the chamber I by flutingthe upper stem m and providing one or more vertical openings m throughthe valve itself that preferably register with the flutes. Upon theunder side of the extension G, at its center, is a small projection g inline with and adapted to engage the upper end of the fluted stem m tomove and hold the valve M off its seat to open the exhaust-port 'i.

To enable the usual communication between the train-pipe and thecar-reservoir to be had when the brakes are off, so that the pressure inthe reservoir maybe the same as in the train-pipe, a channel or groove(Z is provided in the side of the chamber 1) at its lower end, so thatwhen the valve G rests upon its seat h and the piston F is consequentlyat its lowest position air will pass around the side of the piston andthrough a space left beneath the same at the bottom of the chanr berD.Besides its connection with the brakecylinder through the passage-way Lthe valve is also connected therewith by means of a valved port 0, thatconnects the chamber 0 with a chamber P, and a valved port Q, connectingthe latter an d the brake-cylinder connection. The valve R of the port 0is a vertically-movable one, and when closed prevents communicationbetween the chambers C and P, while the the valve S of the port Q is ahorizontally-moving one and is designed to prevent communication fromthe brakecylinder to said chamber P, a coiled spring being provided ineach instance to normally hold the valve to its seat.

Extending downwardly from an arm or extension of the valve R andparallel with the line of movement of the valve is a short stem 1*, thatis in line with a long stem f, extending upwardly from the center of thepiston F. Both of said stems are guided in an opening a formed in asolid portion of the upper casing,and they are out of contact when thevalve extension G of the piston F is upon its seat h and the valve R isupon its seat.

Packing-rings f and g, of usual construction, are respectively employedupon the pis ton F and its extension G, and either the valve-seats orthe valve-faces are provided with gaskets, of leather or other suitablematerial.

The operation of my triple valve is as follows: Air being turned on inthe train-pipe, it will enter chamber C, and passing through the port awill force the piston F down until the lower end of its extension Grests upon the seat h of the chamber II. When in this position, thepiston is a short distance from the bottom of the chamber D and uncoversthe groove or channel (Z, so that air can fiow around the side of thepiston and through the ports or passages E and b into the car-reservoiruntil the pressure in the latter equals that in the train-pipe. Suchpressure (the usual one of seventy pounds) is retained so long as thevalves G and R remain upon their respective seats. To set the brakesslightly, the pressure in the train-pipe is reduced six or eight pounds,which, owing to the now greater pressure from the car-reservoir upon theunder side of the piston F, results in the raising of said piston untilits stem f strikes the stem 1" of the valve B, when it stops, because ofthe greater air-pressure upon the latter. This lifting of the piston Fcarries the under side of its extension G just above the car-reservoirport I), so that air can flow into the chamber II, thence through thepassage K, and through the openings m in the valve M into the chamber Iand then to the brake-cylinder through the passage-way L. No air escapesthrough the duct or port 1', as the valve M rises under pressure of itsspring to close the same as the piston F is raised. The pressure in thecar-reservoir being thus reduced below the train-pipe pressure, theconsequent excess of pressure upon the upper side of the piston willcause the latter to drop sufliciently to cause the closing of thecar-reservoir port I) by the extension G, and as the valve M is held toits seat both by the spring at and the air-pressure upon its under sidewhatever pressure is upon the brakes will be held. By further reducingthe pressure in the train-pipe the action of the piston F will berepeated, and the pressure in the car-reservoir and the brake-cylinderbeing thus equalized the brakes be fully set to make a service stop.

To apply the brakes instantaneously with full force, as when anemergency stop is desired, pressure in the train-pipe is suddenlyreduced ten or twelve pounds. The great excess of pressure thus causedupon the under side of piston F moves the same suddenly upward, and itsstem f, striking the stem r of the valve R with superior force, liftssaid valve and permits a large volume of air directly from thetrain-pipe to flow into and through chamber P and, forcing open thevalve Q, into the brake-cylinder.

As the lifting of the piston extension G uncovers the car-reservoir port2), air will be discharged from said reservoir, as heretofore described,to the brake-cylinder, and, uniting with the air from the train-pipe,result in the production of a large volume of air of an average pressuresufficient to instantly set the brakes. \Vhen pressure inbrake-cylinder, train-pipe, and car-reservoir is equalized, the valve Qis closed, and also the valve R, unless the brakes were applied by thebreaking of the train-pipe. lVhen the latter is the case, only theformer valve closes, preventing return of air through the port closedthereby, while escape of air into the chamber 0 through the port a isprevented by the closing of the latter by the piston F, which is keptraised by the pressure upon its under side. The closing of the valve Qand the holding of the piston F in a raised position thus maintain fullpressure upon the brakes.

The brakes are released by compressing the air in the train-pipe toforce the piston E to its lowest position, and by the engagement of theprojection g of valve G with the fluted stem of the valve M, moving thelatter downward to uncover the duct or passage 2' to permit the escapetherethrough to the atmosphere of the air in the brake-cylinder.

The length of the valve-chamber II is such,

relative to the distance the valve G moves, that at no time is thelatter entirely withdrawn therefrom. It will be noted that I employ noslide-valves, and thus avoid the undue wear of parts which characterizesthis form of valve, and that I operate the emergency-stop valve Rdirectly from the main piston, a feature that simplifies and cheapensthe construction of a triple valve Having thus described my invention,what I claim is- 1. In a triple valve, the combination of the mainpiston, adapted to be acted upon by pressure from the train-pipe and thecar-reservoir, a valve carried by the piston, controlling communicationbetween the car-reservoir and the brake-cylinder, and a perforated IIOvalve in the passage from the reservoir to the cylinder, to control anexhaust-opening, the perforation, or perforations in the valve servingfor the passage of air to the cylinder, substantially as and for thepurpose specified.

2. In a triple valve, the combination of the main piston, adapted to beacted upon by pressure from the train-pipe and the car-reservoir, avalve connected with said piston, within a chamber communicating byseparate passages with the car-reservoir and the brakecylinder,respectively, and a perforated valve in the passage between said chamberand the brake-cylinder, to control an exhaust-opening serving for thepassage of air to the cylinder, substantially as and for the purposedescribed.

3. In a triple valve, the combination of the main piston adapted to beacted upon by WILLIAM E. PRINDLE.

WVitnesses O. A. PIERPONT, ALLAN ISBELL.

